1. Field of the Invention
The invention relates to a stair climbing exercise apparatus. More specifically, the invention relates to such an apparatus wherein the up-and-down motion of the steps of the apparatus is translated to rotary motion, and the rotary motion is transmitted, by a planetary gear arrangement, to a resistance element which provides the exercise resistance.
2. Description of Prior Art
Stairway exercise apparatus are known in the art as illustrated in, for example, U.S. Pat. No. 4,708,338, Potts, Nov. 24, 1987, U.S. Pat. No. 4,676,501, Hoagland et al, June 30, 1987, U.S. Pat. No. 4,720,093, Del Mar, Jan. 19, 1988, U.S. Pat. No. 4,600,187, Schenker, July 15, 1986, and U.S. Pat. No. 4,685,669, DeCloux, Aug. 11, 1987.
The '338 patent teaches an apparatus in which each of the pedals operate independently. Each pedal drives a pedal sprocket, which, in turn, drives a drive sprocket. However, the pedal sprockets drive the drive sprocket only in one direction of travel of the respective pedal sprockets. The drive sprocket, through a transmission system, drives an alternator shaft, and the alternator provides the exercise resistance. The pedals are returned to a rest position by a spring.
In the exercise machine of the '501 patent, which includes foot pads, exercise is performed by shifting the weight of the user from one side to another. Electric motors raise and lower the foot pads.
The stair climbing exerciser of the '093 patent has two steps which are connected, via chains, to sprockets. The sprockets are connected, via one-way drivers, to a flywheel so that the flywheel is rotated only by rotation in one direction of the sprockets. The steps are interconnected for reciprocal motion so that when a user drives one of the steps downwardly, he simultaneously drives the other step upwardly.
The step arms of the steps of the stair climbing exerciser of the '187 patent are connected to either end of a braked rocker plate. The braked rocker plate provides the exercise resistance and also provides reciprocal movement of the two steps.
In the '669 patent, each step of a stair climbing exerciser is connected to the piston of a separate piston and cylinder arrangement. The piston and cylinder arrangements provide the exercise resistance. In addition, the piston and cylinder arrangements are interconnected to provide reciprocal movement of the steps.